The sign of the Sabbath was to show that God gave the Israelites rest from their labors in Israel, to show that He was the one that made them holy, and because God completed His work and rested on the Sabbath. But it was only a shadow of the rest that Jesus gave when He completed His work on the cross and rose from the dead. The Sabbath showed us that as God’s people, His body, we rest in Jesus. He is our Sabbath rest. The Sabbath day is a shadow of the rest we receive in Jesus because of His death & resurrection on the cross. Now we “rest” on Sunday because that is when Jesus finished His work of salvation by rising from the dead, just like God finished His work of creation on the sixth day and rested on the Seventh–Genesis 2:2,3. He is our High Priest who offered His own blood as the spotless Lamb of God. Now His body–those who have faith in Jesus Christ–rests in Him. One day, when He comes back, we will have our permanent rest forever. Read Hebrews 2:17; 3:17-5:10.
Matthew 11:28-30 Come to me all you who are weary and burdened and I will give you rest. Take my yoke upon you and learn from me for I am gentle and humble in heart and you will find rest for your souls. For my yoke is easy and my burden is light.
Reference: Warren, Tony “Who Changed the Sabbath Day to Sunday”, 1996, http://www.mountainretreatorg.net Please read Tony Warren’s article for a complete study on Jesus and the Sabbath day rest.